The aim of the study was to assess the seroprevalence of SARS-CoV-2 IgG antibodies in children hospitalized for reasons other than COVID-19. The study was conducted among 686 children, aged 2 weeks to 18 years, hospitalized in the Department of Paediatrics, Infectious Diseases, and Hepatology in Bydgoszcz, Poland, in the period from 1 June 2021 to 30 April 2022. The presence of anti-SARS-CoV-2 antibodies was detected in 392 (57%) children. Since December 2021, a significantly larger proportion of children with a positive titer of anti-SARS-CoV-2 antibodies has been observed, constituting as much as 87.5% of patients hospitalized in April 2022. In total, 69% of children with detected anti-SARS-CoV-2 antibodies were children under 5 years of age. The highest mean amounts of titers of anti-SARS-CoV-2 antibodies were observed in children over 10 years of age. The conducted studies showed the presence of anti-SARS-CoV-2 antibodies in a significant group of hospitalized children and an increase in the percentage of these children during the fourth and fifth wave of COVID-19 in Poland caused by the Delta and Omicron variants, respectively. The vast majority of parents of the studied children had no knowledge of the COVID-19 infection in their charges, which may indicate asymptomatic infection or mild course of the disease.

The aim of the study was to evaluate tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), soluble intracellular adhesion molecules 1 (s-ICAM-1) and Epstein–Barr virus (EBV) DNA load levels as predictors of hepatological complications of EBV infection in children. The study group consisted of 54 children aged one to eighteen years, who were hospitalised from 1 December 2018 to 31 December 2020 in the Department of Paediatrics, Infectious Diseases and Hepatology and who had hepatological complications in the course of serologically and molecularly confirmed EBV infection. It was shown that IL-6, TNF-α, and s-ICAM-1 concentrations were the highest in patients with hepatitis and biliary pole damage. Higher EBV DNA viremia positively correlated with increased C-reactive protein (CRP) and TNF-α levels and increased leukocyte, lymphocyte, and monocyte counts. Increases in lymphocyte counts and TNF-α concentrations were observed along with increases in gamma-glutamyl transpeptidase (GGTP) activity. Increased concentrations of IL-6, TNF-α, and s-ICAM-1 may indicate the risk of hepatitis with concomitant biliary pole damage during EBV infection.

The aim of the study was to analyze the effectiveness and safety of anti-HCV treatment based on a pangenotypic direct-acting antiviral (DAA) regimen with glecaprevir/pibrentasvir (GLE/PIB) in children. The multi-center study was conducted in HCV-infected children who were treated in the period from November 2022 to January 2023. The analysis included 23 pediatric patients with a mean (SD) age of 9.61 (3.68) years. The cohort included 13 girls and 10 boys. The most common HCV genotypes were GT1b (n = 9, 39.1%), GT1a (n = 6, 26.1%) and GT3 (n = 5, 21.7%). The SVR was assessed at 12 weeks after the end of treatment and was 100% for both girls and boys. The conducted study showed a very good tolerance of the treatment in the entire analyzed group and confirmed a very high efficacy and safety for 8-week treatment with GLE/PIB in children over three years of age. It seems that our study is the first on the real-world use of an 8-week GLE/PIB pangenotypic therapy in a group of children aged 3–12 years and the first in Europe for adolescents aged 12–17.

Most cases of acute infections caused by human herpesvirus 7 (HHV-7) are asymptomatic or very mild. Clinical symptoms disappear spontaneously; however, the infection becomes latent and persists for life with periodic asymptomatic reactivation. Little is known about the virus’s ability to cross the blood–brain barrier. Our case of an immunocompetent infant indicates that HHV-7 infection should be considered a cause of neuroinfection, not only in immunocompromised patients but also in the youngest immunocompetent patients.

Objectives of the study: The aim of this study was to assess the impact of the COVID-19 pandemic on the epidemiology and clinical course of chickenpox in children based on 6 years of self-reported observations. MATERIAL AND METHODS: The medical records of 350 patients under 18 years of age hospitalised in the Department of Paediatrics, Infectious Diseases, and Hepatology between 1 January 2018 to 31 December 2023 were analysed retrospectively. RESULTS: During the analysed period, 350 children were hospitalised due to chickenpox, the fewest in the pandemic period, the greatest number in 2023. Complications of chickenpox were diagnosed in 297 children (84.86%). The most commonly diagnosed complications were bacterial dermatitis (168, 48%) and lower respiratory tract infections (13.42%). After the pandemic period, a generalised inflammatory reaction was observed significantly more often (p ≤ 0.01069). Among children hospitalised in 2023, 5.90% of patients with bacterial dermatitis required surgical intervention due to skin abscess or fasciitis. In 2023, 41.46% of cultures from swabs taken from skin lesions grew Streptococcus pyogenes. After the pandemic, children with chickenpox and gastrointestinal symptoms were hospitalised significantly less frequently (p ≤ 0.00001). CONCLUSIONS: In the post-pandemic period, there were more hospitalisations of patients with chickenpox complicated by bacterial skin infection progressing to a generalised inflammatory reaction or septicaemia, related to the increase in invasive group A streptococcal infections observed in Europe. On the other hand, thanks to the widespread adaption of hygiene practices and infection prevention measures, the number of patients with gastrointestinal symptoms significantly decreased.

The most common causes of acute hepatitis in children are hepatitis A and autoimmune hepatitis. Hepatitis in the course of Wilson’s disease is sporadically registered in adolescents. An increase of activity of aminotransferases both in the course of multisystem inflammatory syndrome in...